The circuit board traces are etched directly on the substrate of the PCB boards. They are also known as pathways. These traces are similar to wires. It is etched on circuit boards to transfer the signal or power to the components of PCBs. For instance, relays, resistors, terminals, capacitor cases, and conductors. Engineers mostly build them with copper foil and design them in a narrow style.

You will be glad to know these traces have transformed the electronic fields. They have eliminated the need for wiring techniques. The manufacturers use them for reliability and as standardized pathways nowadays.

Materials of Circuit Board Traces

Check out these common materials of PCB trace:

●      Copper (Cu)

●      Aluminum (Al)

●      Silver (Ag)

●      Gold (Au)

●      Nickel (Ni)

Copper (Cu)

The material copper (Cu) is commonly used in manufacturing yields. Consequently, in PCBs, it is leveraged to construct thin pathways for transmitting signals. Do you know it offers tremendous characteristics? That makes it an indispensable choice. For example, electrical conductivity, economical prices, and compatibility.

The unique features of copper and its performance help the engineers. It enables them to produce productive electric gadgets. Somewhat it is the most used material due to its durability, reliability, and resistance to handling damaging characteristics.

Properties:

●      High Electrical Conductivity

●      Thermal Conductivity

●      Ductility

●      Economical

●      Resist rust

●      Strength-to-weight ratio

●      Reliability

Applications:

●      Microstrip Transmission Lines: The copper traces are used to improve the high-frequency signals in microstrip transmission lines. You can customize the traces of copper with custom widths and thicknesses.

●      Power Amplifiers: The manufacturers employ copper traces in power amplifiers so that they can distribute the power and regulate the output level.

●      High-Frequency Circuits: Copper traces improve the performance of high-frequency circuits. That includes radar or communication systems. They provide good electrical conductivity and low control resistance.

●      Radio Frequency Identification (RFID): The manufacturer attaches copper traces to the radio frequency identification. That transmits data wirelessly. It is also used for storage purposes.

●      MEMS Devices: These traces are used in microelectromechanical devices. It combines the mechanical and electronic elements on a single trip.

●      Solar Panels: Solar panels are outdoor applications. They required extensive properties of materials that can resist corrosion and critical environmental aspects. That is why the engineer inserts the copper traces in the PCBs of solar panels.

●      Signal Integrity: Copper traces are widely used in electronic devices. That improves the signal integrity. It reduces the electromagnetic interference (EMI) and crosstalk.

Aluminum (Al)

As we all know, aluminum has been used in manufacturing techniques for decades. It is easily available on the market. This metal has excellent corrosion resistance attributes. Aluminum PCB traces are built through a manufacturing process called a metal core.

Using aluminum alloys to construct circuit board traces is pivotal for lightweight products. Its thermal conductivity characteristics help dissipate heat generation during transmission operations.

Properties:

●      Lower Electrical Conductivity

●      Excellent Thermal Conductivity

●      Lightweight

●      Protection from corrosion

●      Durable

●      Reliable

Applications:

●      Cryogenic Electronics: Aluminum traces function as superconducting wiring. That enables the signal supply. This is why it maintains a high power flow at cryogenic temperatures. That significantly needs low temperatures. The cryogenic electronics products are quantum computing or progressive research tools and scientific instruments.

●      Transparent PCBs for X-ray systems: Aluminum traces contain atomic numbers. They are used for their lower X-ray attenuation in X-ray systems. It expertly reduces the absorption of radiation than copper. These traces become transparent when the consumer performs an x-ray of an object. It enables the clear observation results.

●      Nuclear beam applications:

As we have discussed, the aluminum alloys provide good thermal conductivity. Therefore, the manufacturer uses them to make nuclear beam applications. That contains high radiation levels. The aluminum traces manage heat dissipation. Detection approaches, nuclear instrumentation, and particle accelerator electronics use these traces. That helps them reduce heat generation.

●      LED Lighting Systems: LED lighting continues to produce heat during operations. It needs the elements that transfer this excessive heat away. Aluminum traces are the best option to control overheating.

●      Aerospace and Automotive: The consumers harness aluminum traces in various industrial systems. These traces eliminate the overheating during operations. The applications of aerospace and automotive fields are vehicles, aircraft, household products, and consumer devices. That uses the aluminum traces as a heat sink.

Silver (Ag)

Silver is cheaper than gold. It supplies high conductivity to heat and corrosion resistance features. That can enable the improved soldering. The manufacturers harness this material to increase the surface finish of copper. In accordance, it produces a protective layer on the traces of board assemblies.

Properties:

●      Effectively dissipates heat.

●      Highest Electrical Conductivity.

●      Resists oxidation better than copper.

●      Expensive

Applications:

●      Circuit Boards with High-Frequency: The silver traces carry good current capacity. That supports the signal transmission. These traces eliminate the interruption in signals at high frequencies. They are used in RF circuits and products with precise signal transmission.

●      Medical Apparatuses:  Silver traces are used in pacemakers and diagnostic devices. Consumers insert these traces into PCB boards to improve equipment performance. It allows them to collect accurate information from sensitive machines.

●      Military Systems: Silver metal is an economical choice substitute for copper. Therefore, it is widely used in military systems. It protects marine applications from extreme conditions.

●      Consumer Electronics: the manufacturer focuses on making conquer electronics with safety measures. Silver traces provide an additional layer for soldering to the PCB. This increases the application's lifespan and wearability.

Gold (Au)

Gold is an expensive material compared to other metals. But it provides varying properties. You can incorporate this material to create durable traces of circuit boards. Besides its primary features ( corrosion resistance, flexibility, and thermal capacity), it enables strong bonding among wires. This material is biocompatible and melts quickly. The manufacturer can recycle this component for novel yield production.

Properties:

●      Excellent resistance to oxidation and corrosion

●      Biocompatible

●      Surface finish

●      Costly

●      Flexibility

●      Easy to melt

●      Good soldering

●      Lead-free

Applications:

●      Edge connectors and switch contacts: the gold substance is used in PCB to coat the edge connectors and switch contacts. That helps in making a stable connection over time.

●      Microelectronics: the contribution of microelectronics like ICs or semiconductors is high in PCBs. That is why gold is chosen to stabilize its conductive features.

●      Electronic Equipment: Gold-plated columns are used in electronic gadgets such as computers, wearable items, and smartphones. They are connected to the motherboard via secondary circuits.

●      Spacecraft and satellites: The spacecraft and satellite applications use gold traces in PCB to withstand risky climates. These traces control their communication transmission and power systems effectively.

Nickel (Ni)

Nicket material is commonly used to create double-coat layers on copper plates in PCB. The first layers protect the plates from rust and oxidation. Similarly, the second layer extends its longevity. This metal also acts as the barrier between the solder's parts and copper.

Properties:

●      Offer strong resistance to oxidation.

●      Enhance the lifespan

●      Solderability

●      Moderate electrical conductivity

●      Hardness

Applications:

●      ENIG Plating: the electroless nickel immersion gold plating is constructed on PCB. That furnishes an additional layer of protection from oxidation.

●      Plated Through-Holes: the engineer uses nickel in plated through holes. They improve the mechanical strength of multi-layer PCBs.

●      Connectors and contact points: PCBs' connectors and contact points need strong integration for long-term use. Therefore, nickel material is used for soldering and offering harnesses to the components.

PCB Trace Thickness

PCB trace thickness is known as the width and height of the trace. It can be decided depending on the project designs. Usually, the thickness of a circuit board trace ranges from 0.008 inches to 0.240 inches. Consider the following factors when determining the thickness of the PCB trace:

●      Standard thickness

●      Trace width

●      Trace termination

●      Trace size calculator

Standard Thickness

The standard thickness of PCB traces for simple to industrial applications is around 0.5 oz/ft2 to 2 oz/ft2. However, heavy-duty projects with high-voltage power need 6 oz/ft2 or more.

Trace Width

The determination of trace width is commonly fixed and specified by the constructor of the PCB. It refers to the thin line of conducting copper. That carries the signal transmissions.

Trace Termination

The meeting point of traces and pads also helps determine the traces' thickness. The trace width is mainly decided according to the pads' width in the SOIC footprints.

Trace Size Calculator

The manufacturers of PCB also harness trace size calculators to weigh trace thickness. It helps them to choose the appropriate dimensions to avoid overheating and shock risk.

PCB Trace Width Current

The relationship between the PCB trace and the current indicates the transmission capacity. The size of the trace thickness drastically influences the voltage of low to high current power. Therefore, the right size selection is essential to increasing the reliability of the PCB.

Calculating PCB Trace Width for Current:

●      IPC-2221 Standard

●      Factors to Consider

IPC-2221 Standard

IPC-2221 is the most effective approach. That helps the manufacturers determine the accurate size of trace thickness. It indicates several crucial aspects in the form of formulas and charts of current capacity and temperature rise. Look at the chart mentioned below. This will guide you on how to choose the thickness size. It is based on the current capacity for external and internal layers.

Current (Amps)	External Trace Width (mil)	Internal Trace Width (mil)	External Trace Width (mil)	Internal Trace Width (mil)
	(10°C rise)	(10°C rise)	(20°C rise)	(20°C rise)
0.5	6	12	4	7
1	12	24	7	14
2	20	40	12	24
3	30	60	20	40
5	50	100	30	60
10	100	200	60	120
15	150	300	100	200

Factors to Consider

●      Current Flow

●      Permissible Temperature Rise

●      PCB Layer

Design Considerations for Effective PCB Traces

To make your PCB traces more effective, discover the subsequent considerations. This guide will streamline your custom design choices. That will help in protruding improved and functional traces.

●      Trace Width

●      Trace Thickness

●      Trace Length

●      Trace Routing

●      Impedance Control

●      Thermal Management

●      Signal Integrity

●      Grounding and Power Distribution

Trace Width

Determine the trace width of trace via a comparison of current capacity. The IPC-2221 Standard is also helpful for this purpose. Traces with wider widths reduce the chances of overheating, protect the content from oxidation, and decline power loss.

Trace Thickness

The copper thickness in PCB is commonly around 1 oz. However, the increasing demands of high current in application require 2 oz. Therefore, the designers of PCB traces can substitute the trace thickness to enhance the current capacity.

Trace Length

While designing the traces, it is beneficial to keep the length of the traces short. They will enhance the performance of signal transmission. On the contrary, longer lengths cause difficulty in fetching indications and loss signals.

Trace Routing

You must keep the trace routing at 45 degrees instead of 90-degree turns. The sharp edges of the traceroute may interrupt the concentration points and reflect the signals. Furthermore, maintain enough space between routers and other PCB elements. It will reduce the chances of crosstalk. 

Impedance Control

Impedance control is pivotal in high-frequency equipment for controlling signal intensity. It involves the consideration of trace width, spacing, and die electronic thickness measurements.

Thermal Management

Different applications carry specific current flows. The high-power devices produce excessive heat during operations. The designers should choose the proper width and thickness of the trace to dissipate heat. Besides this, heat-sensitive elements should be placed away from high-power traces.

Signal Integrity

You can avoid the signal reflection issue caused by high-power applications. For this, the designers must balance the termination and impedance of traces.

Grounding and Power Distribution

Proper ground planning helps in minimizing the chances of noise. It enables the low-impedance paths for signals. An adequate trace thickness can be used to distribute power evenly. This will eliminate the signal drop issue in high-voltage devices.

Circuit board traces are the standard pathways of circuit boards. They distribute the transmission of signals across all elements. The manufacturer can choose from several materials to construct their desired traces. These traces are widely used in a plethora of applications for signal integrity. The thickness and width of traces directly impact its performance. Therefore, consider the specific aspect while designing your PCB traces with functional qualities.